Transparent films having a nanometer-sized projection/recess structure (nanostructure) have been considered for use in various products such as windows of automobiles and windows of showcase freezers. Patent Literature 1, for example, suggests a configuration in which such a transparent film is used as an anti-reflection film. Known transparent films include hydrophobic or hydrophilic ones, and hydrophilic ones are known to utilize the surface tension of water having entered the gaps (recesses) between the projections to exhibit hydrophilicity, and utilize the capillary action to spread water. Examples of the hydrophilic transparent films include a configuration suggested in Patent Literature 2 in which the projection/recess structure is filled with a hydrophilic polymer.
Also, hydrophilic components allow water droplets to spread on their surface, and are therefore considered for use in the automobile industry and construction industry, for example. Examples of the hydrophilic components include configurations suggested in Patent Literatures 3 and 4 which are utilized in the windows and door mirrors of automobiles.